This invention relates to the art of crushed ice making and more particularly to an improved apparatus and method permitting automatic and continuous crushed ice formation with no relatively moving mechanical parts in the flow path of the water to be frozen or the formed ice.
A variety of ice making apparatus has been evolved for forming crushed ice, and/or for forming elongate columns or blocks of ice.
Thus, Lee et al in U.S. Pat. No. 2,597,008, discloses an apparatus and method for forming crushed ice, in which a column of water is contained within a tube in heat exchange relationship with a refrigerant flow path, with the refrigerant acting to freeze water flowing through the tube. When the water in the tube has been frozen, relatively warm city water main water is directed externally of the tube in a flexible defroster sleeve to defrost the formed ice adjacent the tube wall, and the pressure of the thawing water is employed to expel the ice column from the top of the tube, which is provided with a deflector plate at the tube outlet serving to break the ice being ejected from the tube.
Lee et al in U.S. Pat. No. 2,595,588 attempted to improve on the U.S. Pat. No. 2,597,008 disclosure by utilizing air under pressure introduced into the lower end of the ice forming tubes to eject the formed ice.
Lee et al in U.S. Pat. No. 2,648,955 attempted to improve on the U.S. Pat. No. 2,597,008 disclosure by utilizing a knife blade positioned in the path of the ejected ice to effect crushing of the formed ice.
Hoen, in U.S. Pat. No. 2,768,507 discloses a freezing apparatus for making ice blocks in which a refrigerant jacket is arranged in heat exchange relationship with an ice forming column. Water is sucked upwardly into the column to be frozen, and after freezing, air pressure is employed to eject the formed column of ice downwardly from the freezing column. The formed ice drops into a water supply tank where it is recovered in a receiving device.
The previously evolved apparatus and methods as above described employed relatively complex structures, and methods of operation, in which the ice crushing blade elements require relatively continuous maintenance and replacement due to the crushing action of the ice thereon. Further, in attempting to effect harvesting, it is found in commercial embodiments of these structures that there is a problem in thawing the ice to effect harvesting.